Austin, TX Navien Error Codes

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Navien NPE Error Codes

Troubleshooting tips in RED should be done by your local professionals at Texas Water Heaters.

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Ignition Failure

  • Check if the manual gas valve is open
  • Check the main gas supply
  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Verify that gas pressure is within operating range
  • Check Dual Venturi for proper operation
  • Check DIP Switch settings
  • Check if the igniter is sparking
  • Tighten the ground terminals on the heat exchanger

False flame detection

  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Check if the igniter is sparking
  • Tighten the ground terminals on the heat exchanger

Flame Loss

  • Check if the main gas valve is open
  • Check the intake air filter
  • Check the power supply
  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Verify the incoming gas pressure
  • Check the ground wire
  • Tighten the ground terminals on the heat exchanger
  • Adjust the anti-short cycle time

Heat exchanger overheat

  • Turn OFF the unit, wait at least 30 min, and then restart
  • Clean the inlet water filter and strainer
  • Check the heat exchanger and flush it if required
  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Check the high limit switch and PCB
  • Check pump operation (for A models only)
  • Check the 3-way valve
  • Check DIP Switch settings

Exhaust Overheat: exhaust limit sensor shuts down the unit when the flue temperature exceeds 230 °F for more than 10 seconds.

  • Turn OFF the unit, wait at least 30 min, and then restart
  • Clean the inlet water filter and strainer
  • Check the heat exchanger and flush it if required
  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Check exhaust thermistor and verify [K] value in DIAGNOSTIC mode
  • Check DIP Switch settings
  • Check the water adjustment valve

Abnormal exhaust thermistor open or short

  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Check exhaust thermistor connection
  • Check for proper connection to the PCB

Abnormal Dual Venturi Limit Switch operation

  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Check the Dual Venturi connection
  • Test Dual Venturi for proper operation using TEST mode
  • Check gas orifice for obstructions

Abnormal fan motor activity

  • Check and clean the intake air filter
  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Verify proper voltage and wire connection
  • Check and clean the fan motor

Exhaust blockage

  • Check the intake/exhaust/condensate drain pipe for obstructions.(ice, snow, wildlife, etc)
  • Check and clean the intake air filter
  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • As a temporarily solution for troubleshooting purposes,restart the unit and/or remove the front cover

Abnormal Hot water outlet thermistor open or short

  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Check the thermistor
  • Replace the thermistor

Abnormal Cold water inlet thermistor open or short

  • It's time to a or contact Texas Water Heaters
  • Check the thermistor
  • Verify [C] value in DIAGNOSTIC mode
  • Replace the thermistor

Abnormal Cold water inlet2: thermistor open or short

  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Check the thermistor
  • Check thermistor voltage and resistance values
  • Replace the thermistor

Abnormal water adjustment valve open or short

  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Check the water adjustment valve

Abnormal circulation pump ("A" models only)

  • Check the circulation pump
  • Check water filter for blockage
  • Check the cold water main line
  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Check the flow sensor
  • Set to Internal Recirculation mode and verify flow rate

Abnormal flow sensor

  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Check the flow sensor

Abnormal Hot water inlet2: thermistor open or short

  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Check the thermistor
  • Replace the thermistor

Abnormal mixing valve open or short

  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Check the mixing valve

Abnormal PCB communication

  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Subcode 1~7 PCB > Ignitor: Check the PCB
  • Subcode 8 PCB > Ignitor: Check PCB connection and ignitor
  • Subcode 9 PCB > Fan: Check PCB connection and fan
  • Subcode 10 Abnormal monitoring device of PCB: Check PCB connection and dual venturi
  • Subcode 10~12 Abnormal communication between PCB and Dual Venturi: Check PCB connection and dual venturi

Abnormal dip switch setting

  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Check the dip switches on the front panel and PCB

Abnormal panel key

  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Check the Panel

Abnormal input data

  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Subcode 0 High limit switch of Heat exchanger: Check PCB
  • Subcode 1 Exhaust sensor: check exhaust sensor connection and sensor
  • Subcode 2 Flame rod: check flame rod connection and flame sensor
  • Subcode 3~14 PCB: check the PCB
  • Subcode 15 Below the range of input data from Pressure sensor: check pressure sensor wiring and output voltage of pressure sensor
  • Subcode 16 Over the range of input data from Pressure sensor: check pressure sensor wiring and output voltage of pressure sensor

Abnormal input data

  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Subcode 0 From heat exchanger high limit switch: Check the PCB
  • Subcode 1 Exhaust sensor: Check sensor wiring connection and the exhaust sensor
  • Subcode 2 Flame rod: Check flame rod wiring connection and the flame rod
  • Subcode 3~14 Abnormal memory of PCB: Check the PCB
  • Subcode 15 Below the range of input data from Pressure sensor: Check the Pressure sensor wiring connection and the output voltage of pressure sensor
  • Subcode 16 Over the range of input data from Pressure sensor: Check the Pressure sensor wiring connection and the output voltage of pressure sensor

Abnormal cascade communication

  • Check the Ready-link cable
  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Check the cascade settings
  • Check the PCB version for compatibility

Abnormal outdoor temperature sensor open or short (appears only when the outdoor reset curve is enabled)

  • For you safety and the health of your equipment, Call or Contact Texas Water Heaters for further troubleshooting
  • Ensure that the outdoor reset curve is configured properly
  • Check the outdoor temperature sensor wiring connection

Flushing / Service alarm

  • A heat exchanger flush is required

Abnormal main panel communication

  • Check the PCB

Abnormal flow sensor operation

  • Check the Cold Water line
  • Check the Flow Switch connection